v3.24.3
Fair value of financial instruments - Summary of Quantitative Information About Fair Value Measurements Using Significant Unobservable Inputs (Level 3 Instruments) (Detail) - CAD ($)
 12 Months Ended
Oct. 31, 2024
Oct. 31, 2023
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Derivative related assets $ 150,612,000,000 $ 142,450,000,000
Loans 981,380,000,000 852,773,000,000
Deposits 1,409,531,000,000 1,231,687,000,000
Derivative related liabilities 163,763,000,000 142,629,000,000
Deposits - Personal [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Deposits 522,139,000,000 441,946,000,000
Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Fair value assets 5,404,000,000 5,189,000,000
Fair value liabilities 1,699,000,000 1,938,000,000
Corporate debt and related derivatives [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Loans 1,781,000,000 1,859,000,000
Derivative related liabilities 2,000,000 2,000,000
Government Debt and Municipal Bonds [Member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Corporate debt, related derivatives and other debt 143,000,000 149,000,000
Private equities hedge fund investments and related equity derivatives [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Equities 3,050,000,000 2,732,000,000
Interest rate derivatives and interest-rate-linked structured notes [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Derivative related assets 355,000,000 293,000,000
Derivative related liabilities 900,000,000 995,000,000
Equity derivatives and equity-linked structured notes [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Derivative related assets 21,000,000 111,000,000
Derivative related liabilities 283,000,000 485,000,000
Equity derivatives and equity-linked structured notes [member] | Level 3 [member] | Deposits - Personal [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Deposits 478,000,000 383,000,000
Other [Member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Mortgage Backed Securities 31,000,000 29,000,000
Derivative related assets 16,000,000 5,000,000
Other assets 7,000,000 11,000,000
Derivative related liabilities $ 36,000,000 $ 73,000,000
Bottom of range [member] | Corporate debt and related derivatives [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Credit enhancement 11.70% 11.70%
Bottom of range [member] | Corporate debt and related derivatives [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Credit spread 1.45% 1.89%
Bottom of range [member] | Corporate debt and related derivatives [member] | Price Based [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Prices $ 64.67 $ 9.88
Bottom of range [member] | Government Debt and Municipal Bonds [Member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Yields 6.54% 7.73%
Bottom of range [member] | Private equities hedge fund investments and related equity derivatives [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Liquidity discounts 10.00% 10.00%
Discount rate 8.50% 8.50%
Bottom of range [member] | Private equities hedge fund investments and related equity derivatives [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
EV/Rev multiples 0.70X 1.00X
Bottom of range [member] | Private equities hedge fund investments and related equity derivatives [member] | Price Based [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
P/E multiples 7.30X 6.60X
Bottom of range [member] | Private equities hedge fund investments and related equity derivatives [member] | Market comparable companies [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
EV/EBITDA multiples 3.20X 4.16X
Bottom of range [member] | Interest rate derivatives and interest-rate-linked structured notes [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
IR-IR correlations 48.00% 19.00%
FX-IR correlations (76.00%) 29.00%
FX-FX correlations (74.00%) 68.00%
Bottom of range [member] | Interest rate derivatives and interest-rate-linked structured notes [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Interest rates 1.89% 2.39%
Bottom of range [member] | Interest rate derivatives and interest-rate-linked structured notes [member] | Option pricing model [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
CPI swap rates 1.84% 1.84%
Bottom of range [member] | Equity derivatives and equity-linked structured notes [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
EQ-FX correlations (77.11%) (83.15%)
EQ volatilities 6.00% 6.70%
Bottom of range [member] | Equity derivatives and equity-linked structured notes [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Dividend yields 0.00% 0.14%
Bottom of range [member] | Equity derivatives and equity-linked structured notes [member] | Option pricing model [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Equity (EQ)-EQ correlations 6.30% 32.50%
Top of range [member] | Corporate debt and related derivatives [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Credit enhancement 15.60% 15.60%
Top of range [member] | Corporate debt and related derivatives [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Credit spread 10.90% 9.96%
Top of range [member] | Corporate debt and related derivatives [member] | Price Based [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Prices $ 116.25 $ 107.13
Top of range [member] | Government Debt and Municipal Bonds [Member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Yields 9.55% 10.38%
Top of range [member] | Private equities hedge fund investments and related equity derivatives [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Liquidity discounts 40.00% 40.00%
Discount rate 8.50% 13.30%
Top of range [member] | Private equities hedge fund investments and related equity derivatives [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
EV/Rev multiples 5.72X 5.00X
Top of range [member] | Private equities hedge fund investments and related equity derivatives [member] | Price Based [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
P/E multiples 22.60X 22.60X
Top of range [member] | Private equities hedge fund investments and related equity derivatives [member] | Market comparable companies [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
EV/EBITDA multiples 17.20X 14.90X
Top of range [member] | Interest rate derivatives and interest-rate-linked structured notes [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
IR-IR correlations 86.00% 67.00%
FX-IR correlations 66.00% 56.00%
FX-FX correlations 61.00% 68.00%
Top of range [member] | Interest rate derivatives and interest-rate-linked structured notes [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Interest rates 4.59% 5.18%
Top of range [member] | Interest rate derivatives and interest-rate-linked structured notes [member] | Option pricing model [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
CPI swap rates 1.96% 2.35%
Top of range [member] | Equity derivatives and equity-linked structured notes [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
EQ-FX correlations 50.38% 38.44%
EQ volatilities 146.87% 110.72%
Top of range [member] | Equity derivatives and equity-linked structured notes [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Dividend yields 10.60% 10.71%
Top of range [member] | Equity derivatives and equity-linked structured notes [member] | Option pricing model [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Equity (EQ)-EQ correlations 95.85% 96.49%
Weighted average [member] | Corporate debt and related derivatives [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Credit enhancement 13.00% 13.00%
Weighted average [member] | Corporate debt and related derivatives [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Credit spread 6.17% 5.93%
Weighted average [member] | Corporate debt and related derivatives [member] | Price Based [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Prices $ 92.07 $ 87.66
Weighted average [member] | Government Debt and Municipal Bonds [Member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Yields 7.54% 8.60%
Weighted average [member] | Private equities hedge fund investments and related equity derivatives [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Liquidity discounts 10.40% 16.91%
Discount rate 8.50% 10.70%
Weighted average [member] | Private equities hedge fund investments and related equity derivatives [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
EV/Rev multiples 2.59X 3.00X
Weighted average [member] | Private equities hedge fund investments and related equity derivatives [member] | Price Based [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
P/E multiples 11.27X 8.60X
Weighted average [member] | Private equities hedge fund investments and related equity derivatives [member] | Market comparable companies [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
EV/EBITDA multiples 7.94X 6.93X
Weighted average [member] | Interest rate derivatives and interest-rate-linked structured notes [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
IR-IR correlations Even Even
FX-IR correlations Even Even
FX-FX correlations Even Even
Weighted average [member] | Interest rate derivatives and interest-rate-linked structured notes [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Interest rates Even High
Weighted average [member] | Interest rate derivatives and interest-rate-linked structured notes [member] | Option pricing model [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
CPI swap rates Even Even
Weighted average [member] | Equity derivatives and equity-linked structured notes [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
EQ-FX correlations Middle Middle
EQ volatilities Lower Lower
Weighted average [member] | Equity derivatives and equity-linked structured notes [member] | Discounted cash flow [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Dividend yields Lower Lower
Weighted average [member] | Equity derivatives and equity-linked structured notes [member] | Option pricing model [member] | Level 3 [member]    
Disclosure of significant unobservable inputs used in fair value measurement of assets and liabilities [line items]    
Equity (EQ)-EQ correlations Middle Middle